Technical Field
The present disclosure relates to a gate driver, in particular, a gate driver for driving an inverter.
Description of the Related Art
An inverter is a circuit for converting an AC voltage into a DC voltage, generating an AC voltage by switching a DC voltage converted according to a switching signal by means of a switching element, and outputting the generated AC voltage. Such an inverter can be used to control the drive of a load with high precision by supplying an AC voltage having magnitude and frequency desired by a user to the load.
FIG. 1 shows the configuration of a general three-phase two-level inverter according to a conventional technique. Referring to FIG. 1, a rectifying part 104 of the inverter rectifies a three-phase AC voltage, which is applied from an external power supply 102, into a DC voltage. The DC voltage obtained through this rectification is smoothed by a capacitor CDC. The smoothed DC voltage is converted into a three-phase AC current by means of a switching part 106. The three-phase AC current obtained through this conversion is input to a load such as a motor 108 and is used to drive the load.
The switching part 106 of such an inverter includes a plurality of switching elements S1 to S6. Each of pairs of switching elements (S1/S2, S3/S4 and S5/S6) generates the three-phase AC current through a complementary switching operation which is achieved by a switching signal applied by a gate driver.
Such a gate driver is started only when a driver driving voltage is externally applied to the gate driver. However, it takes a certain time for the driver driving voltage to arrive at a reference voltage appropriate for the drive of the gate driver. The existence of such reference voltage arrival time may cause malfunction of the gate driver, which may result in malfunction and damage of the plurality of switching elements S1 to S6 included in the switching part 106 shown in FIG. 1.